import React, { useState } from 'react'
import B from './B'

 export let context = React.createContext()
export default function A() {
    let [count,setcount] = useState(100)

  return (
    <div>
        <context.Provider value={count} >
        A组件是：
        <B/>
        </context.Provider>
    </div>
  )
}
